Development of a Translational Research Platform to Understand and treat Defective Protein Trafficking in Childhood-Onset Hereditary Spastic Paraplegia

开发转化研究平台以了解和治疗儿童遗传性痉挛性截瘫中的缺陷蛋白贩运

• 批准号: 10406373
• 负责人: Darius Ebrahimi-Fakhari
• 金额: $ 19.6万
• 依托单位: BOSTON CHILDREN'S HOSPITAL
• 依托单位国家: 美国
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-07-01 至 2026-04-30
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10406373
• 关键词: 10 year old; Adaptor Protein Complex Subunits; Adaptor Signaling Protein; Address; Adult; Advisory Committees; Affect; Autophagocytosis; Autophagosome; Axon; Behavior assessment; Biological Assay; Biology; Boston; Brain; CRISPR/Cas technology; Cells; Cellular biology; Child; Childhood; Complex; Corticospinal Tracts; Development; Disease; Disease Progression; Disease model; Fibroblasts; Fluorescence; Foundations; Future; Genes; Genetic Engineering; Genetic Models; Goals; Hereditary Spastic Paraplegia; Human; Image; Immunohistochemistry; Impairment; In Vitro; Individual; Induced pluripotent stem cell derived neurons; Inherited; Integral Membrane Protein; Label; Larva; Lead; LysoTracker; Lysosomes; Measures; Mediating; Mentors; Microscopy; Modeling; Morphology; Motor; Motor Neurons; Nerve Degeneration; Neurites; Neurodegenerative Disorders; Neurology; Neurons; Pathway interactions; Patients; Pediatric Hospitals; Pediatric Neurology; Phenotype; Physicians; Positioning Attribute; Program Development; Proteins; Research; Role; Scientist; Simvastatin; Spinal; Stains; Starvation; Survival Analysis; TFAP2A gene; Testing; Training; Transcription Factor AP-1; Translational Research; Variant; Vesicle; Western Blotting; Wheelchairs; Work; Zebrafish; age related; axonal degeneration; base; behavior test; career; career development; disability; experimental study; human disease; human model; in vivo; induced pluripotent stem cell; knock-down; loss of function; medical schools; molecular phenotype; motor deficit; nervous system disorder; neurodevelopment; neuronal cell body; novel; protein complex; protein phosphatase inhibitor-2; protein transport; restoration; screening; skills; small molecule; spasticity; trafficking; trans-Golgi Network; translational neuroscience; translational pipeline

The hereditary spastic paraplegias (HSP) are a group of over 80 neurodegenerative conditions and the most common cause of inherited spasticity and associated disability. This K08 proposal focuses on prototypical forms of HSP in children caused by biallelic loss-of-function variants in four genes that encode subunits of the adaptor protein complex 4 (AP-4): AP4B1, AP4M1, AP4E1, and AP4S1. Progressive degeneration of the cortico-spinal tracts renders most children with AP-4-associated HSP wheelchair-dependent by the age of 10 years. Currently, there are no therapies that halt disease progression, and few patients are known to have survived into adulthood, highlighting the urgency for research into the fundamental biology of HSP. The AP-4 complex is crucial for the intracellular trafficking of transmembrane proteins, including the autophagy-related protein ATG9A. How altered trafficking of ATG9A leads to impaired neurodevelopment and axonal degeneration and how ATG9A distribution can be restored is currently unknown. In this proposal, I will address this unmet question by developing neuronal models of AP-4 deficiency and testing novel modulators of AP-4-dependent protein trafficking. In preliminary experiments, we have systematically screened small molecule modulators of ATG9A trafficking using a cell-based phenotypic assay that measures ATG9A distribution as a surrogate of AP-4 function. We identified several modulators of ATG9A distribution. I will test the hypothesis that these restore trafficking and function of ATG9A in vitro in neurons derived from AP-4-HSP patients and in vivo in an ap4b1-/- zebrafish model. This proposal presents a five-year research career development program focused on the study of AP-4 in HSP to expand the breadth and depth of understanding the role of protein trafficking and autophagy in this group of diseases. The goal is the establishment of a cross-organismal screening platform to identify and develop novel modulators of protein trafficking for the treatment of HSP. The candidate is currently a resident in Child Neurology at the Department of Neurology at Boston Children's Hospital and Harvard Medical School. The outlined proposal builds on the candidate's previous research on protein trafficking, autophagy and neurodegeneration and integrates new domains of expertise in cell biology, advanced microscopy, and iPSC-derived neurons and genetically-engineered zebrafish to model human diseases. These skills are reflected in his mentoring team consisting of primary mentor, Dr. Mustafa Sahin, and a scientific advisory committee consisting of Dr. Craig Blackstone, Dr. Thomas Schwarz, Dr. Annapurna Poduri and Dr. Leonard Zon. The proposed experiments and didactic work will position the candidate with a unique set of cross-disciplinary skills that will enable his transition to independence as a physician-scientist in the field of translational neuroscience in childhood-onset neurological diseases.

遗传性痉挛性截瘫（HSP）是一组80多个神经退行性疾病，最多 遗传痉挛和相关残疾的常见原因。该K08提案的重点是典型 由双重功能丧失变体引起的HSP形式的四个基因，它们编码的亚基 适配器蛋白复合物4（AP-4）：AP4B1，AP4M1，AP4E1和AP4S1。渐进的变性 Cortico-Spinal束使大多数与AP-4相关的HSP轮椅依赖于10岁的儿童 年。目前，尚无疗法阻止疾病进展，很少有患者患有 活到成年，强调了研究HSP基本生物学的紧迫性。 AP-4复合物对于跨膜蛋白的细胞内运输至关重要，包括 自噬相关蛋白ATG9A。 ATG9A的贩运改变如何导致神经发育受损和 目前未知轴突变性以及如何恢复ATG9A分布。在这个建议中，我将 通过开发AP-4缺乏症和测试新型调节剂的神经元模型来解决这个未解决的问题 依赖AP-4的蛋白质运输。在初步实验中，我们系统地筛选了小的 使用基于细胞的表型测定ATG9A的ATG9A运输的分子调节剂 作为AP-4函数的替代物的分布。我们确定了ATG9A分布的几个调节剂。我会测试 这些恢复源自AP-4-HSP的神经元中ATG9A的运输和功能的假设 患者和体内AP4B1 - / - 斑马鱼模型。 该提案提出了一项为期五年的研究职业发展计划，重点介绍了HSP中AP-4的研究 扩大了解蛋白质运输和自噬在这一组中的作用的广度和深度 疾病。目的是建立一个跨原则筛查平台来识别和开发新颖 用于治疗HSP的蛋白质运输的调节剂。 该候选人目前是波士顿儿童神经病学系的儿童神经病学居民 医院和哈佛医学院。概述的提案基于候选人先前的研究 蛋白质运输，自噬和神经变性并整合细胞生物学专业知识领域， 晚期显微镜和IPSC衍生的神经元和遗传工程斑马鱼以建模人 疾病。这些技能反映在他的指导团队中，包括主要导师，穆斯塔法·萨恩（Mustafa Sahin）和 一个科学咨询委员会，由Craig Blackstone博士，Thomas Schwarz博士，Annapurna Poduri博士组成 和伦纳德·Zon博士。拟议的实验和教学工作将使候选人以独特的方式定位 一套跨学科的技能，将使他能够过渡到该领域的医师科学家的独立性 儿童期神经系统疾病中的转化神经科学。